Soils of Seabee Hook, Cape Hallett, northern Victoria Land, Antarctica

The soils of the Seabee Hook area of Cape Hallett in northern Victoria Land, Antarctica, were mapped and characterized. Seabee Hook is a low-lying gravel spit of beach deposits built up by coastal currents carrying basalt material from nearby cliffs. Seabee Hook is the location of an Adélie penguin (Pygoscelis adeliae) colony which influences the soils with additions of guano, dead birds, eggshells and feathers. A soil-landscape model was developed and a soil association was identified between the soils formed on mounds (relict beach ridges) favoured by penguins for nests (Typic Haplorthel) and the soils in the areas between the mounds (Typic Haplorthel/Typic Aquorthel). Soils formed on the mounds inhabited by penguins contained guano in the upper 50 cm, overlying sub-rounded beach-deposited gravel and sand. Soils between mounds had a thin veneer (< 5 cm) of guano overlying basaltic gravelly sand similar to that in the lower parts of the mound soils. The soils had high concentrations of nitrogen, organic carbon, phosphorus, cadmium, zinc, copper, and increased electrical conductivity, within horizons influenced by penguin guano. Five buried penguin bones were collected from the base of soil profiles and radiocarbon dated. The dates indicate that Seabee Hook has been colonized by penguins for at least 1000 years

Groundwater characteristics at Seabee Hook, Cape Hallett, Antarctica

Seabee Hook is a low lying gravel spit adjacent to Cape Hallett, northern Victoria Land, in the Ross Sea region of Antarctica and hosts an Adélie penguin (Pygoscelis adeliae) rookery. Dipwells were inserted to monitor changes in depth to, and volume of, groundwater and tracer tests were conducted to estimate aquifer hydraulic conductivity and groundwater velocity. During summer (November–February), meltwater forms a shallow, unconfined, aquifer perched on impermeable ice cemented soil. Groundwater extent and volume depends on the amount of snowfall as meltwater is primarily sourced from melting snow drifts. Groundwater velocity through the permeable gravel and sand was up to 7.8 m day−1, and hydraulic conductivities of 4.7 × 10−4 m s−1 to 3.7 × 10−5 m s−1 were measured. The presence of the penguin rookery, and the proximity of the sea, affects groundwater chemistry with elevated concentrations of salts (1205 mg L−1 sodium, 332 mg L−1 potassium) and nutrients (193 mg L−1 nitrate, 833 mg L−1 ammonia, 10 mg L−1 total phosphorus) compared with groundwater sourced away from the rookery, and with other terrestrial waters in Antarctica

Widening of the genetic and clinical spectrum of Lamb-Shaffer syndrome, a neurodevelopmental disorder due to SOX5 haploinsufficiency

Purpose Lamb-Shaffer syndrome (LAMSHF) is a neurodevelopmental disorder described in just over two dozen patients with heterozygous genetic alterations involving SOX5, a gene encoding a transcription factor regulating cell fate and differentiation in neurogenesis and other discrete developmental processes. The genetic alterations described so far are mainly microdeletions. The present study was aimed at increasing our understanding of LAMSHF, its clinical and genetic spectrum, and the pathophysiological mechanisms involved. Methods Clinical and genetic data were collected through GeneMatcher and clinical or genetic networks for 41 novel patients harboring various types ofSOX5 alterations. Functional consequences of selected substitutions were investigated. Results Microdeletions and truncating variants occurred throughout SOX5. In contrast, most missense variants clustered in the pivotal SOX-specific high-mobility-group domain. The latter variants prevented SOX5 from binding DNA and promoting transactivation in vitro, whereas missense variants located outside the high-mobility-group domain did not. Clinical manifestations and severity varied among patients. No clear genotype-phenotype correlations were found, except that missense variants outside the high-mobility-group domain were generally better tolerated. Conclusions This study extends the clinical and genetic spectrum associated with LAMSHF and consolidates evidence that SOX5 haploinsufficiency leads to variable degrees of intellectual disability, language delay, and other clinical features

Soils and hydrology of Seabee Hook, Cape Hallett, Antarctica

The soils and hydrology of Seabee Hook, Cape Hallett, Antarctica were investigated during the 2003-04 and 2004-05 summer periods. Seabee Hook is a low lying spit that has been built up by the deposition of material, from nearby cliffs, by strong tidal currents. Seabee Hook is also the location of a large Adelie penguin (Pygoscelis adeliae) colony and was the location of a USNNZ research base, occupied from 1957-73. A soil map is presented of the Seabee Hook area. A soil association was identified between penguin mounds and intermound areas. Penguins build nests of stones on elevated sites, which at Cape Hallett are relict beach ridges. The penguins have exaggerated the topography of the beach ridges, primarily by adding 3-10 cm size stones ("penguin-stones") and guano, to form penguin mounds. Soils on penguin mounds contain guano in the upper 50 cm of the gravelly and sandy profile, and the guano layer overlies sub-rounded beachdeposited gravel and sand. Soils between beach ridges contain a thin veneer ( <3cm) of guano overlying the same basaltic gravelly sand found in the lower parts of the mound soils. The soils formed on the mounds have been classified usingUSDA Soil Taxonomy as Typic Haplorthels, and the soils formed between mounds have been classified as Typic Haplorthels/Typic Aquorthels depending on their soil moisture contents. The soil of the penguin mounds was enriched in many elements including nitrogen, organic carbon, phosphorus, cadmium, zinc, copper and it had increased electrical conductivity in soil horizons influenced by penguin guano compared to guano free horizons, soils from intermound areas, and soils away from the penguin colony. Radiocarbon dates from five penguin bones buried at the bottom of soil profiles indicate that Seabee Hook has been colonized by penguins for at least1000 years. That the colonization of Seabee Hook may have been rapid is evidenced by the consistent thickness of "penguin stones" and guano on top of the beach ridges throughout the area. Groundwater was situated perched above the ice cement as a shallow (<1-30 cm thickness of groundwater) unconfined aquifer. Groundwater within the penguin colony was sourced from melting snow drifts and ground ice. The occurrence of groundwater within the penguin colony at Seabee Hook showed considerable spatial and temporal variations over the 2003-04 and 2004-05summers, with ice cement levels decreasing from November and groundwater beginning to accumulate in early-December. Groundwater velocity through the permeable gravel and sand (porosity 23-33%) was up to 7.8 m day⁻¹, with hydraulic conductivities of 5 x 10⁻⁴ m s⁻¹ to 5 x 10⁻⁹ m s⁻¹. Groundwater abundance varied on an annual basis depending on the amount of snowmelt occurring during summer. The 2003-04 summer had a higher water table within the penguin colony than the 2004-05 summer. During 2003-04, surface water commonly occurred as ephemeral and intermittent streams and ponds. During2004-05, water was mostly confined to groundwater within the penguin colony, where it occurred in topographic lows. Surface water was present in only a few ponds within the colony during 2004-05, and was more common in the high meltwater zones away from the penguin colony. The penguins and close proximity to the ocean have affected the groundwater chemistry, with groundwater in the penguin colony elevated in salt (14 times more sodium, 41 times more potassium), nitrogen (7 times more nitrate,416 times more ammonia), and phosphorus (33 time more total phosphorus)compared to groundwater sourced away from the penguin colony on Seabee Hookand also compared to other terrestrial waters in Antarctica

Widening of the genetic and clinical spectrum of Lamb–Shaffer syndrome, a neurodevelopmental disorder due to SOX5 haploinsufficiency

International audiencePURPOSE: Lamb-Shaffer syndrome (LAMSHF) is a neurodevelopmental disorder described in just over two dozen patients with heterozygous genetic alterations involving SOX5, a gene encoding a transcription factor regulating cell fate and differentiation in neurogenesis and other discrete developmental processes. The genetic alterations described so far are mainly microdeletions. The present study was aimed at increasing our understanding of LAMSHF, its clinical and genetic spectrum, and the pathophysiological mechanisms involved.METHODS: Clinical and genetic data were collected through GeneMatcher and clinical or genetic networks for 41 novel patients harboring various types of SOX5 alterations. Functional consequences of selected substitutions were investigated.RESULTS: Microdeletions and truncating variants occurred throughout SOX5. In contrast, most missense variants clustered in the pivotal SOX-specific high-mobility-group domain. The latter variants prevented SOX5 from binding DNA and promoting transactivation in vitro, whereas missense variants located outside the high-mobility-group domain did not. Clinical manifestations and severity varied among patients. No clear genotype-phenotype correlations were found, except that missense variants outside the high-mobility-group domain were generally better tolerated.CONCLUSIONS:This study extends the clinical and genetic spectrum associated with LAMSHF and consolidates evidence that SOX5 haploinsufficiency leads to variable degrees of intellectual disability, language delay, and other clinical features